DEVELOPERS: add François Perrad as contact for olimex_imx233_olinuxino_defconfig

François has regularly updated this defconfig in the last few years,
so it makes sense to have him as a contact for it.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Francois Perrad <francois.perrad@gadz.org>
Acked-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>